Our 59 L/Min Maric flow control valves are a non-adjustable precision valve with nitrile control rubbers.   A Maric valve is always installed on every one of our Grundfos submersible bore pumps, the Maric controls the flow out of the pump to a specific maximum flow which in turn means that the pump cannot exceed a known maximum flow.  The pump will operate on a range on the pump curve that is economical and safe, in addition, the Maric will eliminate up-thrust which can often cause damage to bore pumps.   No up-thrust and no high flow cavitation means a much safer and longer lasting bore pump installation.   Manufactured in Australia from DR brass and Watermark Approved, every Maric Precision Flow Control Valve has an operating range of 140 - 1,000 kPa.